Pumpable multiple phase compositions for controlled release applications downhole

ABSTRACT

Pumpable multiple phase compositions for carrying agents and components downhole and controllably releasing them by breaking the suspensions are described. The multiple phase composition may have an external or third phase, which in turn has a first pumpable emulsion internally. The first pumpable emulsion has a second phase containing a first phase which bears the agent to be controllably released. The entire pumpable multiple phase composition may thus be an oil phase-in-aqueous phase-in-oil phase emulsion, or an aqueous phase-in-oil phase-in-aqueous phase emulsion. The agent may be released by one or more of a variety of mechanisms. For example, a water-soluble shale stabilizer could be delivered downhole in an aqueous phase-in-oil phase-in-aqueous phase multiple phase emulsion by injecting the multiple phase composition into a water-based drilling fluid, and then the suspension broken by rotary bit nozzles under high shear stress to release the shale stabilizer at the drilling zone. The multiple phase emulsion compositions of this invention may also be used to deliver agents to remote locations along a conduit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of co-pending application Ser. No.09/363,614, filed Jul. 29, 1999, now U.S. Pat. No. 6,284,714 Whichclaims benefits of Provisional application 60/094,683 filed Jul. 30,1998.

FIELD OF THE INVENTION

The present invention relates to methods and compositions for thecontrolled release of agents and components downhole in an oil recoveryoperation, and more particularly relates, in one embodiment, toemulsions for the controlled release of agents and components downhole.

BACKGROUND OF THE INVENTION

Drilling fluids used in the drilling of subterranean oil and gas wellsas well as other drilling fluid applications and drilling procedures areknown. In rotary drilling there are a variety of functions andcharacteristics that are expected of drilling fluids, also known asdrilling muds, or simply “muds”. The drilling fluid is expected to carrycuttings up from beneath the bit, transport them up the annulus, andallow their separation at the surface while at the same time the rotarybit is cooled and cleaned. A drilling mud is also intended to reducefriction between the drill string and the sides of the hole whilemaintaining the stability of uncased sections of the borehole. Thedrilling fluid is formulated to prevent unwanted influxes of formationfluids from permeable rocks penetrated and also often to form a thin,low permeability filter cake which temporarily seals pores, otheropenings and formations penetrated by the bit. The drilling fluid mayalso be used to collect and interpret information available from drillcuttings, cores and electrical logs. It will be appreciated that withinthe scope of the claimed invention herein, the term “drilling fluid”also encompasses “drill-in fluids”.

Drilling fluids are typically classified according to their basematerial. In water-based muds, solid particles are suspended in water orbrine. Oil can be emulsified in the water. Nonetheless, the water is thecontinuous phase. Oil-based muds are the opposite. Solid particles aresuspended in oil and water or brine is emulsified in the oil andtherefore the oil is the continuous phase. Oil-based muds which arewater-in-oil emulsions are also called invert emulsions.

It is apparent to those selecting or using a drilling fluid for oiland/or gas exploration that an essential component of a selected fluidis that it be properly balanced to achieve the necessary characteristicsfor the specific end application. Because the drilling fluids are calledupon to do a number of tasks simultaneously, this desirable balance isnot always easy to achieve.

It would be desirable if compositions and methods could be devised toaid and improve the ability of drilling fluids to accomplish these tasksby delivering agents and components downhole, which could be releasedcontrollably to accomplish one or more jobs.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide amethod and composition for delivering an agent downhole in a hydrocarbonrecovery operation, particularly during a drilling and/or completionoperation.

It is another object of the present invention to provide a method andcomposition for delivering an agent downhole where the agent is releasedat a controlled time and place.

In carrying out these and other objects of the invention, there isprovided, in one form, a pumpable multiple phase composition, alsocalled a multiple phase emulsion drilling or completion fluid, forcarrying an agent having a first phase, a second phase, and a thirdphase. The first phase is suspended in the second phase to form a firstpumpable emulsion, and next the first pumpable emulsion is dispersed inthe third phase to form the final pumpable multiple phase composition.The pumpable multiple phase composition may be an oil phase-in-aqueousphase-in-oil phase emulsion, or an aqueous phase-in-oil phase-in-aqueousphase emulsion. The agent is present in the first phase.

Additionally, there is provided in one form, a method for releasing anagent downhole beginning by forming a first pumpable emulsion forcarrying an agent. The first pumpable emulsion has a first phasecontaining the agent, and a second phase. The first phase is suspendedin the second phase to form a first pumpable emulsion. The firstpumpable emulsion may be an oil phase-in-aqueous phase emulsion, or anaqueous phase-in-oil phase emulsion, where the agent is present in thefirst phase or is the first phase. Next, the first pumpable emulsion isinjected into a fluid which may be either a drilling fluid or acompletion fluid, such that the external phase of the drilling orcompletion fluid is immiscible with the second phase of the firstpumpable emulsion thereby forming a pumpable multiple phase composition(multiple emulsion). Finally, the pumpable multiple phase composition isbroken downhole to release the agent. The pumpable multiple phasecomposition may be broken by shear, for example, by pumping throughdrill bit nozzles.

DETAILED DESCRIPTION OF THE INVENTION

Pumpable multiple phase compositions (emulsions) are anticipated asbeing useful to organize a liquid phase to isolate one miscible phasefrom another. An oil-in-water emulsion could be used in an invertemulsion, hydrocarbon-based or ester-based or other water immiscible,non-aqueous-based system (forming an oil-in-water-in-oil system), whilea water-in-oil emulsion could be used in an aqueous system (forming awater-in-oil-in-water system). In short, the multiple emulsioncompositions of this invention and methods for their use may be appliedto any two immiscible phases that form stable emulsions. The phases neednot be “oil” and “water”, although such phases are likely to be the mostcommon implementation. One non-limiting example is the combination of awater soluble, relatively high molecular weight glycol that forms anemulsion with brine.

One important application of this kind of organization would be thecontrolled release of the internal phase contents, such as an agentwithin the innermost (first) phase. A non-limiting example of such anapplication would be the emulsion of, for instance, a polyglycol,potassium salt, aluminum salt, calcium salt, a silicate salt, chelate orother shale stabilizer, or an aqueous solution thereof, as a first,internal phase in a hydrocarbon or hydrophobic carrier (second phase)optionally containing an emulsifier and/or stabilizer, and then addingthe emulsion to a water-based drilling fluid. The polyglycol, potassiumsalt, aluminum salt, etc. or other shale stabilizer, alone if liquid, orin solution, e.g., is isolated from the water in the external phase of awater-based drilling fluid. Dilution is prevented, suppressed, ordelayed until the emulsion is broken intentionally. A likely area forbreakage of the emulsion is the high shear environment of and below thedrilling bit, where the shale stabilizer is released to the borehole andcuttings in concentrated form on a localized basis. While the inventiondoes not contemplate, as a preferred embodiment, making the multipleemulsion so stable that it is not broken in a drilling fluid orcompletion fluid application, such stable multiple emulsions areanticipated and may find utility.

Of course, emulsifiers, viscosifiers, or other structural stabilizersmay also be added to increase the mechanical stability of the firstpumpable emulsion in some cases to delay release of the contents(agent).

In more detail, the agent to be delivered as the contents of theinternal phase or the first phase, may be any conventional agent,including, but not necessarily limited to, a shale stabilizer, as notedabove, a filtration control additive, viscosifier, suspending agent,dispersant, thinner, an anti-balling additive, a lubricant (particularlyin the oil-in-water-in-oil multiple phase compositions), a wettingagent, a seepage control additive, a lost circulation additive, drillingenhancer, penetration rate enhancer, corrosion inhibitor, acid, base,buffer, scavenger, gelling agent, cross-linker, catalyst, and the like,and mixtures thereof. Specific useful shale stabilizers include, but arenot necessarily limited to, polyglycols, potassium salts, aluminumsalts, calcium salts, silicate salts, chelates, amines, alkanolamines,alkanolamides, amphoteric compounds, alone if liquid or in aqueoussolutions, and mixtures thereof. Some other specific agents include, butare not limited to amines (failing quartz bonds in certain sands,corrosion inhibitors in clay based systems, shale stabilizers) and metalhalides, e.g. aluminum and thorium halides. The term “acids” in thiscontext includes organic acids and inorganic acids. Such acids can beused to treat cement contamination. If appropriate or desirable, theagent may be in aqueous or hydrocarbon solution.

This first or internal phase should match that of the ultimate fluid inwhich the first pumpable emulsion is to be injected or added. That is,if the first pumpable emulsion is to be injected into an aqueous fluid,the first, internal phase should be aqueous; if the fluid ishydrophobic, the first, internal phase should be hydrophobic.

Of course, the second phase, which together with the first or internalphase forms the first pumpable emulsion, should be of the opposite type.It may be necessary or desirable to add emulsifiers, viscosifiers,stabilizers, and mixtures thereof as structural stabilizers to increasethe mechanical stability of this first emulsion to aid in delayingrelease or breaking. In the context of this invention, emulsifiersshould be understood to include, but are not limited to, surfactants andthe like, and viscosifiers are understood to include, but are notlimited to, gelling agents and the like. The emulsifiers andviscosifiers may be in liquid or solid (e.g. powder) form. Suitableemulsifiers include, but are not necessarily limited to, sorbitan fattyacid esters including sorbitan monooleate and sorbitan trioleate,glycerol fatty acid esters including mono- and/or dioleates,polyglycerol fatty acid esters, polyglycols, alkanolamines andalkanolamides such as ethoxylated amines, ethoxylated amides,ethoxylated alkanolamides, including non-ethoxylated ethanolamides anddiethanolamides, and the like. Viscosifiers and gelling agents include,but are not necessarily limited to, polymers of ethylene, propylene,butylene, butadiene, styrene, vinyltoluene and various copolymers andterpolymers thereof, organophilic clays, aluminum soaps and alkoxidesand other aluminum salts, alkaline earth soaps, lithium soaps, fumedsilica and alumina and the like and mixtures thereof. Other suitablestabilizers include, but are not necessarily limited to, cholesterol andlong chain oil soluble waxy alcohols, and the like. These structuralstabilizers would usually be added directly to the second phase althoughthey may be added to the third phase, if that is more convenient. In onenon-limiting embodiment of the invention, the proportion of structuralstabilizer based on the second phase ranges from about 0.1 to about 90vol. %, preferably from about 1 to about 50 vol. %.

However, the pumpable multiple phase compositions of the invention(emulsions) are designed to be broken in a preferred embodiment. Indeed,they are desirably and rather controllably broken within a certain areaof the borehole at a designated and relatively controlled time.

The preparation of the first pumpable emulsion would typically involvethe mixing of the first phase with the second phase, where anyemulsifier or structural stabilizer is preferably present in the secondphase. The speed of stirring or mixing of the two phases would dependupon the size of the emulsified internal phase droplets desired, and theparticular system used. It is expected that the size of the first phasedroplets would range from about 0.01 to about 1000 microns or less,preferably from about 1 to about 100 microns or less, as non-limitingexamples. In one embodiment of the invention, the first phase dropletswould be as large as is practical. The proportion of first, internalphase to the overall first pumpable composition may range from about 90to about 5 vol. % or less, preferably from about 60 to about 40 vol. %or less, and most preferably, 50 vol. % or less, as non-limitingexamples. A lower threshold of 5 vol. % may be appropriate in someembodiments of the invention.

The formation of the first pumpable emulsion could be accomplishedwithin an injection pump itself. This technique would be similar toin-line mixing the first, internal phase “on the fly” with the secondphase forming the first emulsion before it exits into the third phasefinally forming the multiple emulsion in the mud system.

The first pumpable emulsion is then, in turn, suspended in the drillingand/or completion fluid which is the third phase. This third phase isgenerally to be miscible with the first phase and may contain anemulsifier to help disperse the first pumpable emulsion into suitablesized droplets. Conventional drilling and/or completion fluids may beused as the third phase. If the third phase is oil-based or ahydrocarbon, in a preferred embodiment, the hydrocarbon is a syntheticmaterial, and, for instance, may include, but is not necessarily limitedto, esters, iso-olefins, alpha-olefins, polyolefins, poly-alpha-olefins,paraffins, Fischer-Tropsch reaction products, and the like. The oilphase may be a mixture or blend of petroleum distillates and synthetichydrocarbons. Suitable petroleum distillates include, but are notlimited to, diesel oil, kerosene, mineral oils, food grade mineral oils,paraffinic oils, cycloparaffinic oils, aromatic oils, or n-paraffins,isoparaffins and similar hydrocarbons. Crude oil could be used in somecases. In the case where the second phase is an oil-based phase, it isanticipated that any of these hydrocarbons may be used.

In the case where the multiple phase composition iswater-in-oil-in-water multiple emulsion, the aqueous phase may be brine.Careful adjustment of the internal phase salinity of brine multipleemulsions may be required (osmotic pressure gradient adjustment). Toomuch salt or too low an activity in a first aqueous phase may make thedroplets unstable. However, this mechanism may be intentionally used tocause failure or rupture of the first pumpable emulsion droplets orcapsules downhole. For example, the droplets could be designed to growon the journey downhole and break at or near the desired zone.

It is expected that the size of the droplets of the first pumpableemulsion (first phase in second phase) in the third phase would rangefrom about 10,000 to about 1 micron or less, preferably from about 5 toabout 1,000 microns or less, as non-limiting examples. In one embodimentof the invention, the pumpable emulsion droplets would be as large aspossible. The larger the first phase droplets in the first emulsiondroplets, all things being equal, the easier it would be to break themultiple phase composition to release the agent from the first emulsion.

The proportion of the first pumpable emulsion to drilling and/orcompletion fluid (third phase) may range from about 0.5 to about 90 vol.%, alternatively from about 0.5 to about 40 vol. %, preferably fromabout 1 to about 10 vol. %, in another embodiment from about 1 to about5 vol. %, and most preferably from about 2 to about 6 vol. %, asnon-limiting examples, to make the overall pumpable multiple phasecomposition.

Conventional drilling and/or completion fluid additives may, of course,be employed, including, but not necessarily limited to, wetting agents,viscosifiers, suspending agents, weighting agents, shale stabilizers,filtration control additives, anti-balling additives, lubricants,seepage control additives, lost circulation additives, corrosioninhibitors, alkalinity control additives, thinners, dispersants, and thelike. Indeed, the agents to be delivered by the multiple emulsioncompositions and methods herein may also be present in the third phase.

The method of this invention may find particular usefulness inincreasing the local concentration of an agent downhole after rupture ofthe first pumpable emulsion droplets while keeping the overallconcentration of the agent in the drilling mud (including the entiremultiple phase composition) low. For example, styrene-butadiene rubber(SBR), useful as a viscosifier and/or filtration control additive, couldbe the agent in the first phase of the first pumpable emulsion and be inrelatively low concentrations overall. However, once the first pumpableemulsion droplets are broken or failed, the local concentration of SBRat the droplet failure zone would be relatively increased.

Using the pumpable emulsion composition of the invention isstraightforward and requires no special equipment. The first pumpableemulsion is injected into a fluid that is pumped downhole. The fluid maybe a drilling fluid, drill-in fluid, a completion fluid, or the like. Ina preferred embodiment of the invention, the fluid is a drilling fluidor drill-in fluid. A number of mechanisms could be used to break thepumpable multiple phase composition at a particular time, including, butnot limited to, input of energy, including but not limited to, anincrease in temperature, increase in pressure, increase in shear stressor shear rate, mechanical action (such as a rotating drill bit or drillstring), change in pH, change in electrical potential, solvent thinning,presence of a chemical agent, presence of a catalyst, change in magneticflux, and the like. A non-limiting, but preferred method is breaking themultiple phase composition by subjecting it to a high shear environment,in particular the fluid stream exiting a nozzle impinging on theborehole such as below a bit or opposite a reamer or hole opener. In apreferred method of the invention, the multiple phase emulsion is brokenwithin a required period of time, and within a required physical volume.In one embodiment, if the agent being delivered was a shale stabilizer,the shale stabilizer could be delivered essentially instantaneously tothe borehole and cuttings in a concentrated form on a localized basis.

It will also be understood that more than one agent may be delivereddownhole, and that the two or more agents may interact or react witheach other to provide a beneficial effect. For example, crosslinkerscould be transported in first water-in-oil emulsion in the same aqueousthird phase as a second water-in-oil emulsion containing the agent to becross-linked. Alternatively, two separate internal phases which react oncontact could be delivered in the same first emulsion added to the thirdphase such as an aqueous cross-linker and aqueous polymer solution couldboth be transported in the same first emulsion and added to awater-based mud. Indeed, one reactant could be present in the thirdphase and another reactant could be present in the first phase and thereaction could occur when the boundary of the second phase (firstpumpable emulsion) is broken.

The agent may also be a polymer serving any of the stated functions, ora monomer to be polymerized or in the course of being polymerized tosuch a polymer.

Further, the multiple phase compositions of this invention are notlimited to utility in downhole applications, but could be used todeliver and transport agents along a pipeline or other conduit, such asagents to prevent blockages (e.g. asphaltenes, hydrates, etc.) in asubsea pipeline or the like, or other agents. Any of the agentspreviously mentioned may be used in this way, and suitable agents mayadditionally include, but are not limited to, hydrate inhibitors,asphaltene inhibitors, scale inhibitors, etc.

The invention will be illustrated further with respect to the followingExamples which are not intended to limit the invention but rather simplyto additionally illuminate it.

EXAMPLES 1-7

The following ISOTEQ solutions were mixed:

80/20 I/SMO - 2 g sorbitan monooleate (SMO) was mixed with 8 g ISOTEQ ®isomerized olefin marketed by Baker Hughes INTEQ. 80/20 I/PGO - 2 gLimulse polyglyercol oleate (PGO) was mixed with 8 g ISOTEQ. 80/20I/295/S - 2 g Alkamide DIN-295/S (Rhone Poulenc's linoleamide DEA) wasmixed with 8 g ISOTEQ

All of the above were clear solutions.

The following mixtures of AQUACOL® polyglycol solution marketed by BakerHughes INTEQ were prepared:

50% Aq 5 g AQUACOL with 5 g D.I. water 30% Aq 3 g AQUACOL with 7 g D.I.water 20% Aq 2 g AQUACOL with 8 g D.I. water

The AQUACOL solutions were then emulsified into the indicated ISOTEQsolution at 50/50 wt/wt.

For the 80/20 I/295/S solutions, the following were obtained:

Ex. 2 using 30% Aq: The emulsion was unstable, i.e. it separated almostimmediately. Ex. 3 using 20% Aq: The emulsion was relatively stable,i.e. it formed an emulsion which seemed stable at least short term.

The 20% AQUACOL aqueous solutions were then emulsified into the ISOTEQsolutions at 50/50 wt/wt using a high speed mixer (TISSUE-TEARER byBIOSPEC Products, Inc.). Then 0.5 g of this emulsion was mixed into 9.5g of D.I. water to form multiple emulsions. 80/20 I/SMO (Ex. 4), 80/20I/PGO (Ex. 5) and 80/20 I/295/S (Ex. 6) all seemed to work fairly wellforming multiple emulsions viewed in a microscope.

The 20% AQUACOL aqueous solutions were again emulsified into the ISOTEQsolutions at 50/50 weight/weight using the TISSUE-TEARER as above and0.5 g of the resulting emulsions were mixed with 9.5 g of 12% KCl toform multiple emulsions, but only the composition with 80/20 I/PGOactually formed a multiple emulsion (Ex. 7), the 80/20 I/SMO and 80/20I/295/S seemed to form only simple oil in water emulsions.

After 12 days, the multiple emulsions from 50/50 (wt/wt) 20% Aq inISOTEQ solutions were examined, with the following observations:

Ex. 5: 80/20 I/PGO in D.I. water—Still had ISOTEQ phase droplets withoutside diameters of 2.3 μ to 97μ,but no internal aqueous phasedroplets.

Ex. 7: 80/20 I/PGO in 12% KCI—Still had ISOTEQ phase droplets withoutside diameters 37 μ, but no internal aqueous phase droplets.

Ex. 6: 80/20 I/295/S in D.I. water—Still had external phase dropletswith outside diameters 83 μ diameter, and contained internal aqueousphase droplets.

Ex. 4: 80/20 I/SMO in D.I. water—similar observations to those ofExample 7.

Only 80/20I/295/S of Example 6 actually retained multiple emulsioncharacter with both internal aqueous phase droplets contained withinexternal ISOTEQ phase droplets.

The Examples also show:

the importance of matching the emulsifier to the salinity of the (inthis case) external phase;

the effect of different emulsifiers on multiple emulsion stability;

how internal phase composition can affect emulsion stability; and

how salinity can regulate multiple emulsion stability.

EXAMPLE 8

It is expected that the invention would be implemented as follows. A 20vol. % polyglycol solution in tap water would be prepared using apolyglycol known for its shale stabilizing properties, such as AQUACOL®polyglycol solution marketed by Baker Hughes INTEQ. This solution wouldbe Phase 1. A second phase, Phase 2, would be prepared by adding 20 vol.% of a mixture of glycerol monooleate and glycerol dioleate (equalparts) to 80 vol. % of a C₁₄-C₁₈ isomerized olefin such as ISOTEQ®olefin marketed by Baker Hughes INTEQ. Phase 1 would be gently mixedinto Phase 2 at a 50/50 vol/vol ratio to form a crude, pumpable,emulsion. This emulsion would be added to a water-based drilling fluid(Phase 3) at a concentration of 5 vol. % forming a multiple emulsiondrilling fluid. The multiple emulsion drilling fluid would be formed “onthe fly” while drilling a water sensitive shale prone to balling bitsand stabilizers by addition of the original, pumpable emulsion to thesuction pit of the water-based drilling fluid prior to pumping the fluiddownhole. The concentrated AQUACOL in the Phase 1 droplets would beisolated from the miscible Phase 3 by the hydrophobic Phase 2 film andwould be transported to the bottom of the hole during pumping. Themultiple emulsion droplets would be designed to survive the high shearenvironment of the drill pipe, but not the extreme high shearenvironment below the bit nozzles. The extreme high shear environment atthe borehole wall surface under the bit nozzles as the nozzles blastfluid at the borehole surface would induce rupture of the hydrophobicfilm separating Phase 1 and Phase 3 to expose the borehole to Phase 1.The localized concentration of the AQUACOL shale stabilizer near theexposed borehole wall would be greater than the gross concentration ofthe AQUACOL (20%×50%×5%=0.5%) which would increase the efficiency of theAQUACOL over that achievable by simply adding the AQUACOL to thedrilling fluid at a uniform 0.5 vol. %.

In the foregoing specification, the invention has been described withreference to specific embodiments thereof, and has been suggested aseffective in providing pumpable, multiple phase compositions which caneffectively carry agents and components downhole for controlled releasein space and time. However, it will be evident that variousmodifications and changes can be made thereto without departing from thebroader spirit or scope of the invention as set forth in the appendedclaims. Accordingly, the specification is to be regarded in anillustrative rather than a restrictive sense. For example, specificcombinations of phases, agents, structural stabilizers, etc. andproportions thereof falling within the claimed parameters, but notspecifically identified or tried in a particular composition to improvethe delivery of agents and components herein, are anticipated to bewithin the scope of this invention.

We claim:
 1. A method for releasing an agent downhole comprising:forming a first pumpable emulsion for carrying an agent comprisingsuspending a first phase in a second phase where the agent is present inthe first phase; injecting the first pumpable emulsion into a fluidselected from the group consisting of drilling fluids, drill-in fluidsand completion fluids, thereby dispersing the first pumpable emulsion inthe fluid to create a pumpable multiple phase composition selected thegroup consisting of an oil phase-in-aqueous phase-in-oil phasecomposition, and aqueous phase-in-oil phase-in-aqueous phasecomposition; and breaking the pumpable multiple phase compositiondownhole to release the agent.
 2. The method of claim 1 furthercomprising adding a structural stabilizer to at least one of the phases.3. The method of claim 2 where adding the structural stabilizer occursby adding the structural stabilizer to the second phase.
 4. The methodof claim 3 where the structural stabilizer is selected from the groupconsisting of emulsifiers, viscosifiers, gelling agents, and mixturesthereof.
 5. The method of claim 1 where the breaking the pumpablemultiple emulsion is accomplished by a mechanism selected from the groupconsisting of a change in temperature, a change in pressure, an increasein shear stress, an increase in shear rate, mechanical action, a changein electrical potential, a change in magnetic flux, solvent thinning,presence of a chemical agent, presence of a catalyst, and combinationsthereof.
 6. The method of claim 1 where in breaking the pumpablemultiple phase composition, the breaking is conducted by subjecting thepumpable multiple phase composition to increased shear stress or shearrate.
 7. The method of claim 6 where in breaking the pumpable multiplephase composition, the breaking is conducted by subjecting the pumpablemultiple phase composition to a rotating drill bit.
 8. The method ofclaim 1 in which forming a first pumpable emulsion, the agent isselected from the group consisting of a shale stabilizer, a filtrationcontrol additive, viscosifier, suspending agent, dispersant, thinner, ananti-balling additive, a lubricant, a wetting agent, a seepage controladditive, a lost circulation additive, drilling enhancer, penetrationrate enhancer, corrosion inhibitors, scavengers, catalysts, acids,bases, gelling agents, buffers, cross-linkers, and mixtures thereof. 9.The method of claim 8 in which in forming a pumpable multiple phasecomposition the agent is a shale stabilizer selected from the groupconsisting of a polyglycol, potassium salt, an aluminum salt, a calciumsalt, a silicate salt, a chelate, an amine, an alkanolamine, analkanolamidde, an amphoteric compound, and mixtures thereof, alone ifliquid or in solution.
 10. A method for drilling a well for the recoveryof hydrocarbons comprising: drilling a hole with a rotary drill bit;forming a first pumpable emulsion for carrying an agent comprisingsuspending a first phase in a second phase where the agent is present inthe first phase; injecting the first pumpable emulsion into a fluidselected from the group consisting of drilling fluids, drill-in fluidsand completion fluids, thereby dispersing the first pumpable emulsion inthe fluid to create a pumpable multiple phase composition selected fromthe group consisting of: an oil phase-in-aqueous phase-in-oil phasecomposition; and an aqueous phase-in-oil phase-in-aqueous phasecomposition; and breaking the pumpable multiple phase compositiondownhole to release the agent.
 11. The method of claim 10 furthercomprising adding a structural stabilizer to at least one of the phases.12. The method of claim 10 where the breaking the pumpable multipleemulsion is accomplished by a mechanism selected from the groupconsisting of a change in temperature, a change in pressure, an increasein shear stress, an increase in shear rate, mechanical action, a changein electrical potential, a change in magnetic flux, solvent thinning,presence of a chemical agent, presence of a catalyst, and combinationsthereof.
 13. The method of claim 10 in which forming a first pumpableemulsion, the agent is selected from the group consisting of a shalestabilizer, a filtration control additive, viscosifier, suspendingagent, dispersant, thinner, an anti-balling additive, a lubricant, awetting agent, a seepage control additive, a lost circulation additive,drilling enhancer, penetration rate enhancer, corrosion inhibitors,scavengers, catalysts, acids, bases, gelling agents, buffers,cross-linkers, and mixtures thereof.